Device for Hydrodynamic Intertwining of Fibers in a Fiber Web

ABSTRACT

A device is known in which the bulky felt arriving on the top side of an endless belt for water felting is compacted between a felting drum and the belt and at the same time it is wetted by a first water curtain from a nozzle beam, whose water jets first pass through the endless belt and then the fiber web and finally the felting drum. Now, according to the invention, the unconsolidated felt is held against the bottom of an endless belt by means of induced suction and transported, and it is brought up tangentially to a needle felting drum, arranged beneath the endless belt. In this way, the handover of the fiber web from the endless belt to the needle felting drum is accomplished under the influence of gravity.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a 371 National Stage of International PatentApplication No. PCT/EP2005/005697, filed on May 27, 2005, which claimspriority from German Patent Application No. 10 2004 030 413.0, filed onJun. 23, 2004, both of which are incorporated by reference herein. TheInternational application was published in German on Jan. 5, 2006 as WO2006/000282 A1 under PCT Article 21(2).

FIELD OF THE INVENTION

The present invention relates a device for hydrodynamic intertwining inorder to compact the fibers of a web made from one or more of naturaland synthetic fibers.

SUMMARY OF THE PRIOR ART

A compacting device is described in European Publication Patent No.EP-A-0 859 076. The compacting device acts to compact bulky feltarriving on an endless belt for a water felting process carried outbetween a felting drum and two belts, at the same time it is wetted by afirst water curtain from a nozzle beam whose water jets pass through theendless belts, the fiber web and the felting drum. A similar process isdisclosed by European Patent Publication No. EP-A-0 818 568, in whichtwo felting drums arranged one above the other are used for compactingboth sides of the web.

The known device per the '568 Publication addresses the problem of slowcompression of a fiber web consisting of loose, unconsolidated fibersthat receive upstream wetting in the pressed condition. Even for lighterfelts, a danger exists that the loose fibers as they are being compactedwill be forced into the felting drum to get caught there and causeproblems upon removing the fiber web after the felting process iscompleted. Also, the device produces a negative slack in the fiber web,which is detrimental to the ultimate strength of the fiber felt.

International Patent Publication No. WO 2004/046444 proposes a processfor better loosening the fiber web after the felting process byarranging and orienting the nozzle beam so that the water jets of thebean hit the fiber web in its direction of transport only after the lineor region of compression is passed. This process step cleans away thefibers picked up by the endless belt immediately after or during aneedle felting step. A second endless belt is passed around the needlefelting drum to increase resistance on the drum during felting whiletransporting the fiber web onward in a tension-free condition. Ininstances where this second endless belt is not desirable, effectivetransport of the fiber web may no longer be assured.

SUMMARY OF THE INVENTION

A device for hydrodynamic intertwining in order to compact the fibers ofa web made from natural and/or synthetic fibers of any given kind, andpreferably free of bonding agents, includes:

-   a) a first conveyor belt transporting the fiber web and a subsequent    endless belt, which is stretched and deflected between at least two    rollers,-   b) a first needle felting drum, coordinated with the endless belt    and with at least one first nozzle beam, preferably across the    working width of the web,-   c) at least one second nozzle beam having water jets that are    directed against a back side of the endless belt and, through the    endless belt, against the fiber web and against the first needle    felting drum, at least for the wetting of same, while the endless    belt is brought up tangentially to the first needle felting drum,    above the conveyor belt and the first needle felting drum,-   wherein the fiber web, supported solely on an outer sider of a lower    slack portion side of the endless belt, is transferred after a first    needle felting by means of the at least one second nozzle beam    downward onto the first needle felting drum,-   e) wherein the slack portion of the endless belt, transporting the    fiber web, is further coordinated at its slack portion with a    suction box under at least a partial vacuum, above the slack portion    of the endless belt and the needle felting drum, in order to support    the fiber web, and-   f) wherein the endless belt, transporting the fiber web on its slack    portion, being coordinated with a conveyor belt upstream from it,    which is supported between idler rollers and passes off the fiber    web, transports the fiber web on a tight portion of the conveyor    belt and hands the fiber web off to the slack portion of the endless    belt.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more readily apparent from the DetailedDescription of the Invention, which proceeds with reference to thedrawings, in which:

FIG. 1 provides a schematic view of a device for hydrodynamicintertwining of fibers in a fiber web that follows principles of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is further described in detail herein and by wayof example, with reference to a preferred embodiment of the invention asdepicted in FIG. 1. In a frame 1 of FIG. 1 there is shown a compactingwater felting unit with two needle felting drums 2, 3 for processing afiber web 8. This unit may normally be the first unit of a larger waterfelting layout for an unconsolidated fiber web, and therefore otherfelting drums (not shown) may in addition be hooked up to the frame 1,with the web 8 running in meandering manner around these additionalfelting drums for further processing on both sides of the fiber web 8.

The unit further includes an endless belt 4, which is passed aroundseveral rollers 5, which are tautly held and able to rotate in a supportframe (not shown), while a slack portion 4′ of the endless belt 4 isbrought up tangentially to the top side of the first felting drum 2. Thefiber web 8 arrives from the conveyor belt 6, which can be, for example,an exit belt of a carding machine that carries the fiber web 8 on itstop side. An initially bulky fiber web 8 travels on this endless belt 6in the direction of the arrow 7, toward the unit. At the end of theconveyor belt 6, and above the conveyor belt 6, is located the slackportion 4′ of the endless belt 4, which is arranged to run in parallelwith the conveyor belt 6 in the direction of the arrow 7. Anunconsolidated fiber web 8 is held against the lower end of the slackportion 4′ by means of a suction box 9. Preferably, at least a partialvacuum is created on the bottom side of the slack portion 4′ of theendless belt 4 by placing the suction box 9 directly above the slackportion 4′.

The suction box 9 acts along the length of the slack portion 4′ of theendless belt 4 as far as the needle felting drum 2. As shown in FIG. 1,the slack portion 4′ lies above a rear idler roller 6′ of the endlessbelt 6 and the needle felting drum 2. A rear idler roller 6′ of theendless belt 6 lies roughly in the region of the front idler roller 5 ofthe endless belt 4 and the rear idler roller 6′ lies somewhat behind thesurface of the upper needle felting drum 2. The suction box 9 holds thefiber web 8 against the lower side of the slack portion 4′, which issealed off against the belt 4 by means of the suction box 9. At a distalend of the suction box 9, the fiber web 8 is pressed between the endlessbelt 4 and the drum 2 and at the same time it is wetted by means of anozzle beam 10 operable across the width of the fiber web 8, and isneedle felted by the belt 4. The liquid applied by the nozzle beam 10 isat least partly sucked away beneath the drum surface by means of asecond suction box 2′, which is provided inside the needle felting drum2. Importantly, the fiber web 8 is led down over the needle felting drum2 in the direction of the arrow 11. The water jets from the nozzle beam10 are acting from top to bottom, or in the direction of gravity. Thehanding off of the fiber web 8 from the slack portion 4′ to the drum 2is also accomplished from top to bottom. Thus, this orientation of thenozzle beam 10, slack portion 4′ and needle felting drum 2 supports theloss-free hand-off of the still unconsolidated fiber web or felt 8 tothe first needle felting drum 2, which is further coordinated with twonozzle beams 12, 13 fully capable of needle felting. In a similarfashion, a loss-free hand-off of the fiber web 8 is accomplished betweenthe needle felting drum 2 and a second needle felting drum 3.

After processing by the second needle felting drum 3, a consolidatedfelt 8 can then be dried or further processed, e.g., perforated orembossed, for which a belt 14 with additional nozzle beams 15 may beoptionally be provided.

As is shown by the direction of arrow 11 in FIG. 1, the two needlefelting drums 2, 3 are driven to turn in opposite manner and the fiberweb 8 is wound around them in meandering fashion, so that the fiber webcan easily be processed on both sides. The needle felting drum 2, aswell as the following needle felting drum 3, are each outfitted with oneor more nozzle beams 12, 13 and suction boxes 2′, 3′ to carry outassociated needle felting operations.

1. A device for hydrodynamic intertwining in order to compact the fibersof a web made from one or more of natural and synthetic fibers, thedevice comprising: a) an endless belt which is stretched and deflectedbetween at least two rollers to define a slack portion of the endlessbelt for receiving the fiber web from a second conveyor belt, b) a firstneedle felting drum, coordinated with the endless belt and with at leastone first nozzle beam for needle felting processing of the web on thefirst needle felting drum, and c) at least one second nozzle beam,having water jets that are directed against a back side of the endlessbelt and, through the endless belt, against the fiber web and againstthe first needle felting drum, at least for the wetting of same, whilethe endless belt is brought up tangentially to the first needle feltingdrum, above the conveyor belt and the first needle felting drum, d)wherein the fiber web, supported on a lower side the slack portion ofthe endless belt, is capable of being transferred after a first needlefelting along the endless belt 4 by means of the at least one secondnozzle beam downward onto the first needle felting drum, e) wherein theslack side portion of the endless belt transporting the fiber web isfurther coordinated with a suction box under at least a partial vacuum,the suction box being positioned above the slack portion of the endlessbelt and the needle felting drum, in order to support the fiber web, andf) wherein the second conveyor belt, which is supported between at leasttwo idler rollers, transports the fiber web along a tight portion of theconveyor belt and hands the fiber web off to the slack portion of theendless belt. characterized in that the first needle felting drum isfollowed by a second needle felting drum with at least one coordinatedthird nozzle beam, the second needle felting drum turning in a directionopposite to a turning direction of the first needle felting drum, suchthat the fiber web is passed around the first and second felting drumsin meandering fashion and then directed to a third endless belt forfurther processing.